1. Field of the Invention
The present invention relates, in general, to amusement park rides and payload delivery systems in which orientation of a payload such as a vehicle is controlled and selectively adjusted, and, more particularly, to a motion-driven positioning assembly for use in amusement park rides and other payload delivery systems using a cam assembly or mechanism to provide selective and/or continuous positioning of a payload such as passenger vehicles about a drive axis (or with 360-degree or full rotation of a positioning mechanism, such as a rotatable shaft, to selectively position attached vehicles or other payloads relative to a guide or ride track).
2. Relevant Background
Within the amusement park industry, there are many rides where it is desirable to alter the orientation of a vehicle as it moves along a track (e.g., a guide or ride track). For example, a themed show may be presented adjacent the track of a ride on either side of the direction of travel. In these rides, it may be desirable to rotate the vehicle body to better allow the passengers to view the show or experience a special effect.
As will be appreciated, there are many instances within theme or amusement parks that utilize controlled orientation of a payload on a moving platform such as guest compartments or bodies on ride vehicles or animated set pieces that may move about on a guide track system (e.g., the show portion of a ride may itself include show pieces moving about on a track with rotating or changing orientation payloads or aspects). Outside of the amusement park industry, tracks are used to guide payloads through factories and other settings with it often being desirable and useful to rotate or change the orientation of the payload relative to the direction of travel or the guide track.
Currently, amusement park rides typically use a mechanical earn system or a controlled motor-driven system to achieve a desired payload orientation along a vehicle track. An exemplary mechanical cam-based ride may include a payload platform that rotates as a cam follower or the cam itself contacts a surface near the guide track as the arm or platform moves in a direction of travel along the track. Mechanical cam systems are simple, reliable, repeatable, and provide a high level of assurance that a particular orientation of the payload will be achieved at a given point along the vehicle track. A drawback, though, of cam systems is that they only provide a limited angular variation around the cardinal orientations (e.g., forward along the track, backward along the track, track left, and track right). For example, many cam systems only allow the payload such as a passenger compartment to be rotated 45 degrees to the left or right relative to the guide track (or direction of travel). It is typically not possible, using existing cam orientation or positioning systems, to selectively rotate the payload over a full range without eventually encountering the end of possible rotation. At this point, further rotation in the current direction is no longer possible and the only rotation available or that can be provided is back in the opposite direction (have to rewind the payload or cam system in some senses).
Motor driven positioning or orientation systems are useful for providing an unlimited range of motion including rotating a payload in either rotation direction to any coordinate in a 360-degree range, but motor driven systems present other design challenges to designers of amusement park rides or others attempting to orient a moving payload relative to guide track. For example, a motor-driven system generally requires electrical power on the vehicle, which forces a designer to provide provisions for failure of the power or motor system (e.g., failure to rotate or unpredictable moves during a controller fault). In many cases, this causes a ride designer to increase the ride envelope provided near the vehicle to make sure that even a failed position or orientation would pass through the envelope (e.g., increase a diameter of a tunnel such that even if a support arm fails in an extended or outboard position the vehicles will not contact the tunnel wall). Generally, this means that motorized systems cannot be used in close proximity to fixed elements such as set pieces and secondary devices may have to be provided to stop a vehicle from entering an area with its payload or vehicles in an unplanned or non-design orientation such as an emergency stop if a misaligned guest compartment is coming into a station area on a ride. Further, motor driven systems often require accurate and continuous measurement of the vehicle track position and orientation of the payload to provide proper control over the drive mechanisms and achieve desired positioning of the payload. In other words, the workspace of the vehicle has to be extended to all possible positions the vehicle is capable of achieving such that designers of such systems have to make sure nothing can collide with the workspace envelope.
There remains a need for improved positioning methods and systems for payloads such as passenger compartments that are moved along a ride path or track. Preferably such methods and systems would allow for smaller or tighter envelopes about the guide track to reduce space requirements and allow for desired ride effects (such as a near miss of a ride vehicle when a tunnel is approaching or is getting smaller). Also, it is typically desirable that the positioning methods and systems be adapted to provide an unlimited range of motion or rotation while also providing reliable positioning in critical situations (e.g., a guaranteed safe position of a passenger compartment along a guide track relative to set pieces or an envelope boundary).